POS0106 THE MCP2 AND WRIST PLUS 2 TENDONS ARE THE MOST AFFECTED AND RESPONSIVE JOINTS/TENDONS OUT OF THE ‘US7 SCORE’ IN PATIENTS WITH RHEUMATOID ARTHRITIS – AN OBSERVATIONAL STUDY
Authors: A. F. Podewski, A. M. Glimm, I. Fischer, G. Bruyn, P. Hanova, H. B. Hammer, A. B. Aga, E. A. Haavardsholm, S. Ramiro, G. R. Burmester, M. Backhaus, S. Ohrndorf
Journal: Annals of the Rheumatic Diseases (2022)

Background There is no international consensus on an optimal ultrasound scoring system in patients with rheumatoid arthritis (RA) yet. Objectives To assess the musculoskeletal ultrasound score on seven joints (‘US7 score’) (1) for the identification of the most frequently pathologic and responsive joint regions during 3 and 6 months of therapy in order to optimize the score. Furthermore, to evaluate the impact of disease duration on the performance of the score. Methods RA patients were recruited from 54 German rheumatology centers when starting or changing DMARD therapy. Patients were assessed by the US7 score in greyscale (GS) and power Doppler (PD) at baseline, after 3 and 6 months. The frequency of pathologic joint/tendon regions and their responsiveness to therapy were assessed including the comparison of palmar vs. dorsal regions. Differences between the palmar and the dorsal sides were analyzed using Chi-square test, the gradings of the US-joint inflammation were compared between baseline, 3 months, and 6 months by Friedman test with Dunn test as post-hoc test. We used standard response mean to determine the responsiveness of possible reduced scores and linear regression to assess the amount of information retained from the original score. Analyses were also performed separately for early and established RA. Results A total of 435 patients (n=138 early RA) were included (56.5 (SD 13.1) years old, 8.2 (9.1) years disease duration, 80% female). The dorsal wrist, palmar MCP2, extensor digitorum communis (EDC) and carpi ulnaris (ECU) tendons out of 7 joints were most frequently affected by GS/PD synovitis/tenosynovitis (wrist: 45%/43%; MCP2: 35%/28%; EDC: 30%/11% and ECU: 25%/11%) and significantly changed within 6 months of therapy (all p≤0.003 in GS/PD). The dorsal vs. palmar side of the wrist by GS/PD (p&lt;0.001) and the palmar vs. dorsal side of the finger joints by PD (p&lt;0.001) were more frequently pathologic. The reduced US7 score (GS and PD: dorsal MCP2, dorsal wrist, EDC and ECU, only GS: palmar MCP2) showed therapy response (SRM 0.433) after 6 months and retained 76% of the information of the full US7 score. No major differences between the groups of early and established RA could be detected. Conclusion The wrist, MCP2, EDC and ECU tendons were most frequently pathologic and responsive to therapy, representing an optimized score for monitoring of RA patients for both early and established RA and should therefore be included in comprehensive scores for monitoring RA patients. References [1]Backhaus M, Ohrndorf S, Kellner H, Strunk J, Backhaus TM, Hartung W, et al. Evaluation of a novel 7-joint ultrasound score in daily rheumatologic practice: a pilot project. Arthritis Rheum. 2009;61(9):1194-201. Acknowledgements We thank Gabriela Schmittat for logistical support in the study. Disclosure of Interests Annika Franziska Podewski: None declared, Anne-Marie Glimm: None declared, Imma Fischer: None declared, George Bruyn: None declared, Petra Hanova: None declared, Hilde Berner Hammer Speakers bureau: Paid speaker for Lilly, Novartis and AbbVie, Employee of: Advisory board for AbbVie, Anna-Birgitte Aga Speakers bureau: AbbVie, Eli Lilly, Novartis, Pfizer and UCB, Consultant of: AbbVie, Eli Lilly, Novartis, Pfizer and UCB, Espen A Haavardsholm: None declared, Sofia Ramiro Speakers bureau: Eli Lilly, MSD, Novartis, UCB, Consultant of: AbbVie, Eli Lilly, MSD, Novartis, Pfizer, UCB, Sanofi, Grant/research support from: AbbVie, Galapagos, Novartis, Pfizer, UCB, Gerd Rüdiger Burmester: None declared, Marina Backhaus Speakers bureau: Speaker fee from AbbVie, BMS, Galapagos, UCB, Novartis, Sarah Ohrndorf: None declared